Contaminated areas along the San Francisco Bay could be inundated

As water levels rise, old landfills, shipyards and industrial sites that line the San Francisco Bay are at risk of being submerged, exposed to higher storm surges and inundated by groundwater. Toxic substances, including arsenic, lead, petroleum products, asbestos and DDT that have been sealed off could leech into groundwater or into the Bay.

While the agencies that have a hand in keeping the Bay clean consider sea level rise in new clean-up projects, they can’t necessarily revisit every old one, according to reporter Nate Seltenrich, who wrote about the problem in this week’s East Bay Express.

“There’s a good likelihood that containment measures that were put in place before sea level rise, and may still be effective now, will no longer be effective,” Seltenrich told me. “The real challenge is money. The costs that could be associated with going back and retrofitting any previously contained site, it’s really expensive.”

In his article, Seltenrich wrote that there are forty or more sites that will be affected by sea level rise:

Among the most contaminated locations are Alameda’s Naval Air Station, Richmond’s United Heckathorn site (a former shipyard and agricultural chemical warehouse), and San Francisco’s Hunters Point Naval Shipyard. Other cities containing waterfront toxic sites include Oakland, Hayward, Newark, Hercules, Rodeo, Antioch, Novato, Tiburon, Sausalito, South San Francisco, Redwood City, San Mateo, and East Palo Alto; Richmond has more waterfront toxic sites than any other city, with a total of nine.

There are eight Superfund sites near the Bay, according to EPA Region 9 Director Jared Blumenfeld. The EPA factors sea level rise into its clean-up plans, and it reviews each Superfund site every five years. But Blumenfeld says these big sites won’t necessarily be the biggest problems as the sea level rises.

“There are everyday operations that would need to be examined, from a mechanic’s shops to dry cleaners, that have the potential to be toxic,” he said. With sea levels projected to rise three feet or more in the next century, businesses that handle chemicals on a daily basis could be flooded.

Bruce Wolfe of the San Francisco Bay Regional Water Quality Control Board echoed that view.

“We wouldn’t necessarily single out what might be called toxic sites, we would say that any site that has the potential for waste to get into either surface water or groundwater is a concern,” he said.

“Historically we have used the Bay margin as a place to put disposal sites, so we’ve always had this challenge to manage sites that are adjacent to the Bay, be they landfills or the military sites,” Wolfe added. “So this just adds another layer of challenge.”